1. Field of the invention:
This invention relates, in general, to aerodynamically-shaped flying toys and, in particular, to saucer shaped flying toys having a sound emitting whistle means on the surface thereof, said whistle means generating an intermittent sound when the toy is tossed through the air and spun in either direction about its axis at sufficient combined angular and translational velocity.
2. Description of the Prior Art:
Saucer-shaped flying toys have become very popular in the last several decades. One such family of saucers is marketed by the Wham-O Manufacturing Company of San Gabriel, California under the registered trademark FRISBEE. U.S. Pat. No. 3,359,678 issued to Edward E. Headrick and assigned to the Wham-O Manufacturing Company describes the aerodynamic principles of one saucer toy of this type. The usual embodiment of a saucer shaped flying toy is made of a plastic material and has a central portion with a depending rim located at the edge of the central portion. The rim has a thickness somewhat greater than the central portion. The rim curves downwardly from the central portion and has a configuration such that the saucer when viewed in elevation approximates the shape of an airfoil.
A wide variety of throwing games use a flying saucer shaped toy as an integral element. The toy is gripped by placing the thumb on the convex side of the toy and one or more fingers on the concave side thereof. The toy is thrown with a snap of the wrist which imparts a spinning motion to the toy upon release from a thrower's hand.
The aerodynamics of saucer shaped flying devices are not well known, but it is believed that the flight of hand propelled saucer shaped toys can be analyzed in terms of certain factors controlled to a substantial extent by a thrower. These factors include spin, forward motion, attitude, direction and force. Spinning the toy imparts gyroscopic motion to the toy which stabilizes the toy throughout its flight. The aerodynamic factors controlled by the user all influence lift and as a consequence, the flight characteristics of the toy. Saucer shaped toys have been compared to an airplane wing moving through the atmosphere. The upper airfoil surface of the wing generates a reduced pressure area to create most of the lift forces acting on the wing. A lesser amount of lift is provided by an area of increased pressure on the lower side of the wing. It is believed that a saucer shaped flying toy behaves in an analogous manner. The center of lift of a flying disk is very near its center of gravity so that a spinning disk maintains stability during flight, aided by the gyroscopic effects imparted by spin. Two other factors obviously under user control are the direction of flight and the amount of translational and rotational force imparted to a saucer shaped flying toy. Factors beyond the immediate control of a user include wind force and the design of the toy itself. Science Digest, June, 1978, at pages 73-75, discusses aerodynamics of the FRISBEE.
With regard to design, the Headrick U.S. Pat. No. 3,359,678 provides a means located on the convex side of a saucer shaped flying toy for interrupting the laminar flow of air. Air flows over a smooth aerodynamic surface in a laminar flow regime which provides a smooth decrease in the velocity of air as the surface is approached. At a distance from the surface the air has a freestream velocity, while at the surface the relative velocity is zero. The zone near the surface in which the air velocity is significantly slowed is called the boundary layer. The resultant frictional drag force of the airstream reduces the airstream momentum and slows the wing. The means for interrupting, or spoiling, the smooth flow of air provided by the Headrick U.S. Pat. No. 3,359,678 is a series of concentric ridges, positioned on the convex surface of the toy. Under certain flight conditions, a turbulent boundary layer over the convex side of the saucer results, with corresponding reduction of drag and increased lift.
Various types of sound generating devices on the saucer shaped flying toys and similar articles are known in the prior art. The Holt U.S. Pat. No. 3,900,987 discloses a dome-shaped body having a number of whistles on the outer periphery thereof. The whistle design disclosed is such that the whistles can operate only in one direction of rotation. Each whistle has an air inlet opening partially facing the one operative direction of rotation of the dome-shaped body. An air scoop surrounds each air inlet. This device will not emit a whistle sound if it is spun in an opposite direction. For example, a right-handed toss would activate the whistle while a left-handed toss would not activate the whistle. The air scoop also unduly restricts rotational velocity, detracting from performance and may prevent the velocity necessary to activate the whistle.
The Meyer U.S. Pat. No. 3,959,916 discloses another type of saucer shaped flying toy which has a vibrating reed contained inside a passageway formed in the rim of the toy. The passageway openings are flush with the rim surface. It is believed that the laminar flow along the surface of the rim prevents activation of the sound generating mechanism.